Consider Mark Sanchez

The modern quarterback must be cunning. The position requires a player who can forsake the deliberative comforts of the huddle to stand above center, scan the opposing defensive formation, and, like Napoleon, whose theory of battle was on s’engage, et puis on voit (you enter the fray, and then you see what to do), make rapid play-calling decisions. Omaha. Hut. Snap. Touchdown passes are fine, but in today’s game the desideratum is a quarterback who possesses the accuracy to minimize turnovers, and the presence of mind to avoid being sacked. Meanwhile, in response to the public dismay over long-term effects of football-related concussions, the league has swathed the quarterback in a crinoline of new rules of the game, which make it more difficult for pass rushers to legally hit him—advantages that further enhance the aristocratic primacy of the position. It is the most important role in American team sports.

Given how crucial the quarterback is to his team’s success, and given the months of immersive preparation that every team’s scouts, personnel men, and coaches devote to the annual draft, in April, you’d think that N.F.L. teams would be unerring evaluators of promising college quarterbacks. But that is not the case. Of the four N.F.L. quarterbacks who will lead their teams into this weekend’s conference championship games, only one, Peyton Manning, of the Denver Broncos, was a first-round draft choice. The San Francisco 49ers’ Colin Kaepernick was taken in the second round. The Seattle Seahawks chose Russell Wilson in the third round. And the New England Patriots’ Tom Brady, whom many inside the sport consider the finest quarterback of his time because he wins with marginally gifted receivers, was, famously, a low-sixth-round choice. Brady embodies the N.F.L. truism that forecasting talent, though always necessary, is often futile.

This year, as many as four college quarterbacks may be chosen among the first ten picks of the draft. N.F.L. front-office men are currently spending their days inside locked, windowless war rooms, reviewing sheaves of scouting reports and loops of game film as they parse the risk parity of Louisville’s Teddy Bridgewater, debate how well Texas A. & M.’s Johnny (Football) Manziel will survive the big-time hits and the big-city nights, predict if and when Central Florida’s Blake Bortles’s throwing will win him enough attention to out-Google his oft-searched girlfriend, and analyze whether Fresno State’s Derek Carr is a keeper or more like his brother, the fizzled former No. 1 over-all choice David Carr. As these draft teams labor, they’ll keep in mind picks like the Falcons’ second-round selection in 1991. After seeing their rookie attempt a total of four unsuccessful passes that year, Atlanta traded Brett Favre to Green Bay. The draft specialists also keep in mind J. P. Losman.

“Remember J. P. Losman?” the former Raiders quarterback Rich Gannon, now a CBS broadcaster, asked. “He was a first-round pick for Buffalo out of Tulane [in 2004]. You take Tom Brady, Peyton Manning, and J. P. Losman out to the park in shorts for a workout, and all of us would take J. P. Losman. He was faster, had a bigger arm, and he’d blow you away in the workout. But from the shoulders up, how good is he?”

“Manning doesn’t throw the ball as well as he did. He’s coming off neck surgery,” Gannon continued. “How’s he breaking everybody’s records? The game has slowed down for him. He sees what other people don’t see.” Losman, meanwhile, has been “on the street,” as N.F.L. personnel men say, since 2011.

What does it take to succeed as an N.F.L. quarterback? Not so long ago, football was a more freewheeling sport, and quarterbacking statistics reflected it. In the nineteen-seventies, when quarterbacks were urged to think of the passing game in high-reward, “vertical” terms, a fifty-per-cent passing-completion rate was the acceptable standard. Today, when short crossing patterns—in effect, thrown running plays—are a crucial feature of the game, every team craves a sixty-per-cent passer. (Nine of the twelve most accurate passers in N.F.L. history are active.)

“Comparing quarterbacks twenty years ago with quarterbacks today is like comparing a Cadillac twenty years ago to a Cadillac of today,” the retired N.F.L. head coach Dick Vermeil said. “They just do it better today.” (Vermeil’s quarterback in 1999, when he led the St. Louis Rams to a Super Bowl victory, was that modern progenitor Kurt Warner, a career 65.5 per-cent passer—tied with Manning for the fourth best in N.F.L. history.)

The signal feature of today’s offensive coördinators is that they draw from the entire tactical history of the sport to build their game plans. They are modificationists, and as a result, Vermeil estimates, the offensive-call volume is four times what it was twenty-five years ago. A contemporary quarterback can adjust the entire look of his offense from play to play, putting more pressure on the opposing defense—so long as he is capable of mastering the eclectic trove of calls. “Everybody wants to change personnel on every play, but not everybody is Peyton Manning,” Tom Moore, a retired N.F.L. passing impresario, said. Moore was the Colts’ offensive coördinator for the duration of Manning’s career there.

A generation ago, a young quarterback was expected to apprentice for a season or two on the sidelines before assuming control of a team. “The older-style West Coast quarterbacks took longer to develop, perhaps because they hadn’t played in a [high-tech] offense at earlier levels, and because top college quarterbacks were inevitably drafted by poor teams,” the retired Bills coach Marv Levy said. Jim Plunkett, Dan Pastorini, and Archie Manning were all drafted in 1971 by lousy franchises. For them, Levy noted, “it wasn’t a matter of succeeding; it was a matter of surviving.” Today, quarterbacks who are drafted in the first round cost enough money against the salary cap that they are usually expected to lead their teams right away. Most do have the advantage of having played in pro-style passing offenses in college. Still, as significant as the position of quarterback is, football remains fundamentally a team game. Even a superior quarterback can’t expect to thrive if the players around him, and the offensive coördinator’s preferred style of play, don’t complement his skills. The second-year Colts quarterback Andrew Luck is a fine player, but part of the reason he became successful so quickly is that he joined a talented team.

For all the promise that Luck, Kaepernick, and Wilson have demonstrated in reaching the N.F.L. playoffs, the sustained excellence of Brady and Manning is very rare. Consider Mark Sanchez. After being selected by the Jets in the first round of the 2009 draft, Sanchez and a team of fine veteran players went to consecutive A.F.C. championship games—and had a 3-2 record against Brady’s Patriots. In 2010, Sanchez led N.F.L. quarterbacks with six game-winning drives. The next two seasons, however, he regressed, throwing an alarming flurry of interceptions and becoming the butt of an infamous N.F.L. collision. He missed the entire 2013 season owing to a preseason shoulder injury that required surgery. At the moment, he is a career fifty-five-per-cent passer, with sixty-eight touchdown passes and sixty-nine interceptions. That portfolio is sufficiently modest that the Jets could cut him.

Yet several former players and coaches think that N.F.L. teams in need of a quarterback ought to consider signing Sanchez instead of drafting one of those enticing collegians. “So many times, quarterbacks are the victim of the team they play on,” Vermeil told me. “Sanchez took his team to the playoffs. That means he can do it again. Sometimes it takes moving to another place for a guy like him.”

“The fans have beat the hell out of him. Other teams have beat the hell out of him. The quarterback’s not the only one at fault,” Vermeil said. “He takes most of the blame, but normally there’s an accumulation of reasons. Coming out of college, everybody thought he was a fine player. We all saw it.”

After leaving the Colts, Tom Moore was hired as an offensive consultant by the Jets, in 2011. The time he spent with Sanchez at the team’s facility left him with a favorable impression of the then twenty-four-year-old passer’s strength of arm, recall, and personality. “I did like him, and always will like him,” Moore told me. “He started out hot. He slipped a little, and then he got injured. I think he is a special talent. You have to do it quick, and he can. He works hard…. Archie Manning was as fine a quarterback as ever went down the pike, and he never went to a playoff game. Not a good quarterback—a great one. Lot of it has to do with the team.”

Gannon, the former Raiders quarterback, also worked with Sanchez as an off-season consultant. He found much to admire in Sanchez’s athletic abilities, but like many of the Jets talent evaluators I came to know while writing a book about the team, Gannon questioned Sanchez’s ability to make winning decisions under pressure. The Sanchez I knew was a compelling person, but he was young—and he seemed young; from the first, Brady and Manning were old football souls. Gannon attributes part of Sanchez’s erratic play to the lack of continuity in New York, where he had to adjust to a stream of new receivers, as well as three different offensive coördinators. Brady has played only for offensive coördinators who were promoted through the Patriots system. Similarly, Manning, the Saints’ Drew Brees, and Aaron Rodgers, of the Green Bay Packers, have thrived by playing within one scheme throughout their careers. Sanchez has had to start anew three times. “It’s French to Spanish to Greek,” Gannon said. “Too hard.”

Gannon has reason to be sympathetic to Sanchez’s plight: his own experience as a player found him cycling through a series of coaches and systems in Minnesota, Washington, and, finally, Kansas City. “Only after seven years did I finally learn how to break down an opponent,” he said. He signed with Oakland in 1999, where, at the age of thirty-four, he suddenly became a Pro Bowl quarterback.

Another late-to-flourish quarterback was Jim Plunkett. Like Sanchez, Plunkett grew up in California, in a Hispanic family. He played college football to acclaim in his home state, winning the 1970 Heisman Trophy, and then came east as a young man. He joined the Patriots, whose yielding offensive line and frequent reliance on option running plays is at least partially to blame for Plunkett’s brutal succession of injuries. But, like Sanchez, Plunkett was tough. Six weeks after a surgery to place a pin in his left shoulder, Plunkett played again and was hit so hard the pin popped out of the bone. New England eventually traded him to San Francisco; the 49ers soon released him. “I was very depressed,” Plunkett told Sports Illustrated’s Rick Telander. But then, in 1978, Plunkett became a Raider, and after two years of reserve duty, at thirty-three, he led the team to the Super Bowl and was named M.V.P. Given their luck with withershins quarterbacks, Sanchez might soon be Oakland’s man.

Tom Flores, Plunkett’s former head coach with the Raiders and a quarterback specialist, is one who thinks Sanchez can thrive. “Did all of a sudden Sanchez become a bad quarterback? No.” Flores said. “Jim Plunkett had some of that [adversity]. He didn’t resurface until ten years later. Why that happens is not easy to say.”

Plunkett was a political-science major at Stanford and a particularly introspective football player—the sort of person who lingered on his interceptions rather than on his touchdowns. Sanchez is more optimistic by nature. But watching him founder across the 2011 and 2012 seasons, he seemed to me to have lost the fluid intuition for his position that all the best players exude. And now he has been absent from the game for a year. Most of the books that offer deep insight into football are not really football books, and Sanchez’s struggles bring to mind a passage from John Williams’s great novel of the West, “Butcher’s Crossing,” in which a skilled buffalo hunter who has been away from the prairie describes the uncertainty he feels as he sets off on a new expedition: “I just have to get the feel of the land again. I’ve been watching too close, trying too hard to remember.”

Manning and Brady both missed seasons because of serious injuries and then returned with their intuitions for a white-lined, hundred-yard range completely intact. But as we watch them face one another in Denver this weekend, we should appreciate that they are the rarest of athletes. As Dick Vermeil came to understand during his long career, most quarterbacks are built of so many ambiguous, conflicting features that even expert eyes have difficulty seeing them clearly.

As a young man, Vermeil was Plunkett’s quarterback coach at Stanford. “When I coached Plunkett, they were thinking of making him a linebacker.” Vermeil recalled, almost fifty years later. “I read a lot of war books now that I’m retired. The thing I notice is nobody can predict who will win the Medal of Honor. It’s never who they think. They’re cut from different sizes and shapes and environments. Quarterbacks are the same way. Who could predict Kurt Warner would do what he did? I couldn’t, and I signed him. Kurt Warner was better on game days under pressure. How do you predict that?”

Nicholas Dawidoff’s most recent article for the magazine, “Quarterback Shuffle,” was published in September, 2012, and he is the author of the book “Collision Low Crossers.”